A. Technical Field
The present invention relates generally to protection of electrically sensitive components, and more particularly, to the use of gas discharge systems and methods of using the same to protect electrically sensitive components.
B. Background of the Invention
Certain electronic components, such as semiconductor components, can be very sensitive to voltage levels. As data communication devices have increased in performance and processing speeds, they have also increased in susceptibility to damage from voltage spikes, such as from electrostatic discharge (ESD). For example, Vertical Cavity Surface Emitting Laser (VCSEL) transmitters may be damaged by ESD events of 100 volts or more.
Excess voltage levels may result in catastrophic failure of the components. Alternatively, excess voltage levels may create latent defects that degrade the components performance and/or its lifespan. Components so affected may create diagnostic problems because the latent defects may not be detectable. Thus, a defective component may initially test within acceptable limits, but its actual, later performance may be substandard or unacceptable.
A number of devices have been employed to minimize the damage caused by voltage spikes. Threshold voltage devices, gas discharge tubes, and diodes have been used to clamp voltage surges and electrostatic discharge (ESD) voltage spikes in discrete circuits, circuit boards, and communication/data systems.
Such protection mechanisms are not, however, possible for all applications. For example, electrical discharge protection of high speed devices, such as VCSELs, is not possible using these devices due to the high speeds at which these devices operate, and/or due to their extreme sensitivity to ESD damage. Existing protection methods incorporate excess capacitance into the protected assembly, degrading its performance at high data rates. Existing gas discharge protection methods, while adding little capacitance, are too bulky and have breakdown threshold voltages too high to protect these high speed devices. Since existing techniques for excess voltage protection involve added input capacitance, and usually protect against greater than 100 volts, these techniques are not suitable for protection of some components, such as VCSEL devices.
Accordingly it is desirable to provide protection of electrically sensitive components but without drastically affecting the component's or system's performance.